1. Technical Field
The present invention is directed toward reinforcing structures for reinforcing concrete moldings and more particularly toward a trussing member for constructing three-dimensional re-mesh structures and a method of building such three-dimensional re-mesh structure.
2. Background Art
The use of trussing members for connecting reinforcing bars is known in the reinforced concrete art. One reinforcing structure incorporating trussing members is known as "MEDICO" produced by Metal Steel Products, Co. The MEDICO structure is a "girder type" reinforcement structure formed by welding an undulating "saw tooth" bar between parallel spaced apart bars at the peak of each saw tooth undulation.
Such structures have numerous shortcomings. First, because the truss members (i.e., the undulating bar) are welded to the parallel spaced apart reinforcing bars, the structure cannot be easily altered in the field. Second, such structures are bulky and relatively difficult to store and transport because they cannot be readily bent or rolled. Lastly, such structures have limited utility in that they are not suitable for use in many three-dimensional concrete moldings because they provide little reinforcing normal to the plane of parallel spaced apart bars.
It is also know in the art to build three-dimensional re-mesh structures by welding diagonally extending "trusses" or wires between parallel, spaced apart re-mesh or welded wire fabric sheets. Once example of such a structure is used in the "Insteel 3-D.TM. panel" manufactured by Insteel Construction System, Inc. of Brunswick, Ga. In this structure, "truss" bars or wires extend diagonally between parallel wires of the spaced apart re-mesh sheets in the plane defined by the parallel wires of the spaced apart re-mesh sheets. The "truss" wires angularly diverge from each other to form truss-like connections between the re-mesh sheets.
Structures of this type are used principally as a reinforcing frame for wall panels such as the "Insteel 3-D.TM. panel", and as two layer reinforcing for concrete slabs.
These three-dimensional re-mesh structures have a distinct advantage over the "girder type" reinforcing structures discussed above in that they provide three-dimensional reinforcing. However, these three-dimensional structures also have problems similar to the "girder type" reinforcing structures. For example, the three-dimensional structures cannot easily be altered in the field, they are bulky and they are difficult to transport. In addition, these three-dimensional structures require special care in storing to avoid deforming the structure.
Another embodiment of three-dimensional re-mesh structures known in the art employs an undulating "saw tooth" reinforcing wire welded to parallel but laterally off-set wires of parallel, spaced apart re-mesh sheets. Adjacent undulating reinforcing wires are both welded at their peaks to the same reinforcing wire of the top re-mesh sheet. The undulating reinforcing wires diverge from this top sheet and are welded to wires of the subjacent re-mesh sheet that are adjacent to each other and laterally off-set from the reinforcing wire of the top sheet. This structure may be used in the same manner as three-dimensional structures discussed above.
This structure has an advantage over the structures shown in the "Insteel 3-D.TM. panel" in that it provides a greater ability to resist forces normal to the plane of the re-mesh sheets; however, it has the same storage and handling problems.
The present invention is directed towards overcoming one or more of the problems discussed above.